Performance of three tropical hair sheep breeds.

The performance of three hair sheep breeds (Brazilian Somali, Morada Nova, and Santa Ines) was evaluated in the production environment of northeastern Brazil. Data from a total of 524 lambs sired by 21 rams and out of 190 ewes were analyzed. These data were collected from 1980 to 1983 at Sobral, Brazil from an experiment designed to compare performance of the three breeds. The traits included weights of lambs at birth, weaning, 8 mo, 10 mo, and yearling ages and ewe characters of weight at lambing (EWT), total lamb weight born (LWB), total lamb weight weaned (LWW), and prolificacy rate (PR). Differences (P < .01) among breeds were found for all characters. The Brazilian Somali, the smallest and slowest-gaining breed, was less sensitive to yearly variation than were the other breeds. The Santa Ines, the largest and fastest-gaining breed, was superior in LWB and LWW per ewe lambing. Averaged over the 4-yr period, the Morada Nova had the highest PR (1.82), and the Brazilian Somali and Santa Ines had similar PR (1.39 and 1.31, respectively). Environmental effects on PR due to yearly rainfall quantity and distribution pattern influenced lamb growth up to weaning and ewe reproduction performance. Breed x year (P < .05) interaction effects on PR were largely attributable to the Somali breed's exhibiting higher PR than the Santa Ines and Morada Nova breeds during the relatively wet years of 1981 and 1982.     

Abscesses and caseous lymphadenitis in goats in tropical semi-arid north-east Brazil

Summary This study reports the incidence of abscesses in relation toCorynebacterium pseudotuberculosis infection in goats in north-east Brazil. Among 656 goats examined periodically over almost two years 41·6% were found with superficially palpable abscesses. Most of the infected areas were in the anterior half of the body in front of the pre-scapular region; the inguinal region formed the other prominent area. Among 486 dead or slaughtered goats, 56 (11·5%) revealed abscesses in the internal organs. Lungs and epididymis were affected most, liver, spleen, udder and lateropharyngeal nodes were next in order and kidneys and mediastinal nodes were least affected. Thus the overall incidence of external and internal abscesses was 28·8%; of all the abscesses 27·7% were due toC. pseudotuberculosis and the rest due to infections ofCorynebacterium pyogenes and several species of streptococci or staphylococci. The growth ofC. pseudotuberculosis-infected and non-infected goats was of the same order and it seems that caseous lymphadentitis is not the cause of much financial loss in north-east Brazil but in view of its high incidence remedial measures should be considered necessary in regions where the goat meat industry is likely to become more intensive and important.

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Resumen Este estudio informa sobre la incidencia de abscesos en cabras del nordeste de Brasil. Se examinaron 656 cabras periódicamente durante dos a?os, de las cuales 41·6% se encontraron con abscesos superficiales palpables. Las áreas infectadas correspondieron a la mitad anterior del cuerpo, frente a la región pre-escapular y a la región inguinal. De 486 cabras muertas o faenadas, 56 (11·5%) revelaron abscesos en los órganos internos. De estos, los mas afectados, en orden descendente fueron: pulmones, epididimos, hígado, bazo, ubre, nódulos linfáticos faríngeos, ri?ones y nódulos linfáticos mediastínicos. La incidencia general de abscesos externos e internos fue de 28·8%. De todos los abscesos 27·7% se debieron aCorynebacterium pseudotuberculosis y el resto aC. pyogenes y a especies deStreptococcus y Staphylococcus. El crecimiento de cabras infectadas y no infectadas conC. pseudotuberculosis fue similar, lo que sugiere que la linfadenitis caseosa no ocasiona muchas pérdidas económicas en el nordeste de Brasil pero en vista de su alta incidencia medidas de control deben ser consideradas en regiones donde la industria de carne caprina pueda llegar a ser mas intensiva e importance.

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Résumé Parmi 656 caprins examinés périodiquement pendant presque deux ans, 41,6 p. 100 ontété trouvés porteurs d'abcès palpables superficiels. Dans la plupart des cas, la zone infectée se trouvait dans la moitié antérieure du corps, à l'avant de la région pré-scapulaire. La région inguinale constituait la deuxième zone la plus infectée. Sur 486 animaux morts ou abattus 56 (11,5 p. 100) ont montré des abcès internes affectant en premier lieu les poumons et l'épididyme. Le foie, la rate la vessie, les ganglions pharyngienslatéraux venaient ensuite dans l'ordre. Les ganglions rénaux et médiastinaux étaient les moins affectés. La incidence des abcesses externes et internes a étè de 28,8 p. 100. Globalement, 27,7 p. 100 des abcès étaient dus àC. pseudotuberculosis. le reste àC. pyogenes et à quelques espèces de staphylocoques et streptocoques. la croissance des caprins infectés ou non parC. pseudotuberculosis était à peu près identique et il semble que la lymphadénite caséeuse n'entra?ne pas beaucoup de pertes financières dans le Nord-Est brésilien mais étant donné sa fréquence élevée, des mesures curatives devraient être considérées comme nécessaires dans les régions où l'industrie de la viande de chèvre a des chances de devenir plus intensive et plus importante.

     

Simulation of genetic and environmental interaction of three tropical hair sheep breeds.

The Texas A&M Sheep Simulation Model was used to examine genetic-environmental interactions (GEI) among Brazilian Somali, Morada Nova, and Santa Ines breeds and type and level of feed supplement in northeast Brazil. Two sets of simulations were conducted to examine effects of different supplement quality (napier grass vs cunha legume) and quantity (napier grass only). The analyses indicated the benefits from supplementing lambs at weaning during the dry season and from supplementing lactating ewes at the beginning of lambing season when forage is scarce. The cunha legume was an effective supplement, but choosing between cunha legume and napier grass is an economic consideration. Increasing the amount of napier grass supplement per ewe from 200 g/d to 400 g/d resulted in a significant GEI (i.e., different levels of response such as lamb mortality rate, lamb weaning weight, and lambing rate for different breeds). The Brazilian Somali was the least responsive, whereas the Santa Ines was the most responsive to supplementation. It was concluded that the level of supplement should be higher for the Santa Ines and Morada Nova than for the Somali. The amount of supplement should be regulated so that it neither substitutes for nor lowers the utilization of the native caatinga forage. None of the breeds was simulated to be superior in all environments. Thus, considering the wide range of resources of individual farmers, any one of these breeds may be the preferred choice, depending on the individual set of production resources.     

Investigation in early growth traits, litter size, and lamb survival in two Iranian fat-tailed sheep breeds

In the present study, 1,635 lambing records of Ghezel (n?=?766) and Mehraban (n?=?869) breeds were used to evaluate the early growth traits, litter size, and lamb survival in sheep reared in Fars Province, southern Iran, during a 5-year-long period. The least squares means (± SE) of lamb birth weight for Ghezel were 5.27 (±0.22), 5.02 (±0.22), and 3.98 (±0.23) kg for single males, single females, and twin lambs, respectively; whereas, the corresponding values for Mehraban were 4.39 (±0.18), 4.18 (±0.18), and 3.50 (±0.19) kg. The least squares means of pre-weaning lamb growth (gram per day) for Ghezel were 239 (±15), 218 (±15), and 181 (±16) for single males, single females, and twin lambs, respectively, and the corresponding values for Mehraban were 204 (±12), 187 (±12), and 156 (±13). Lambs from 2 year old ewes or younger were on average lighter at birth and at weaning and had a lower average daily gain than those from older ewes (P?<?0.05). The percentage of twin births increased from 1.1 and 1.3 % for ewes aged ≤ 2 years to 19 and 12 % for those aged ≥ 6 years old in Ghezel and Mehraban, respectively (P?<?0.05). The mean pre-weaning lamb mortality was 7.1 and 4.1 % for Ghezel and Mehraban, respectively.     

Genetic parameters for birth weight,growth, and litter size in Nordic sheep breeds

Abstract

In this study, genetic parameters were estimated for the Danish populations of Danish Marsk, Finnish Landrace, Gotland Pelt and Spel for birth weight (BW), average daily gain until two months (DG2) and litter size (LS). A multivariate animal model was used for estimation of genetic parameters, including fixed effects, both direct and maternal additive genetic effects, common litter effects and permanent environmental effects. Mean birth weight and DG2 ranged from, respectively, 3.39 kg and 262 g to 4.61kg and 286 g. Litter size ranged from 1.60 to 2.07. Direct heritability for BW ranged from 0.12 to 0.24, and maternal heritability for BW was about 0.23 for all breeds. Direct heritability of DG2 ranged from 0.19 to 0.33. The heritability for LS was between 0.08 and 0.13. The significant genetic correlations between the direct and maternal effect on both BW and DG2 were negative. The genetic correlations between the growth traits and LS were not uniform.     

PrP genotyping of Austrian sheep breeds

Scrapie, an ovine and caprine transmissible spongiforme encephalopathy, is widely spread among sheep populations in many European countries. As it is known that susceptibility to scrapie is determined genetically, breeding programmes aiming at providing scrapie-resistant flocks have been established. Selection is based on the prion protein (PrP) genotype, which is used to classify animals into risk groups of susceptibility (R1-R5) according to the amino acids encoded by codons at positions 136, 154 and 171, respectively. At position 136 (136V-->136A) alanine and at position 154 (154H-->154R) as well as 171 (171Q-->171R) arginine are the favoured amino acids. Whereas PrP genotyping data are available for many of the European sheep breeds, comparable data for local Austrian sheep breeds are missing. The most known among these are Tyrolean mountain sheep, forest sheep. Tyrolean stone sheep and Carynthian sheep. The genotypes of 112 sheep from these four local breeds were determined. In terms of PrP genetics, Austrian breeds belong to the group of non-valine-breeds, with the exception of the Carynthian sheep, that exhibited a frequency of 136V of 4.2%. The most frequent allele was ARQ with 64.6-71.2% (depending on the breed), followed by ARR (14.8-25.8%). In contrast to the above-mentioned findings, scrapie has never been diagnosed in any of the Austrian sheep breeds. Native Austrian sheep breeds exhibit a very robust constitution, a pronounced adaptation to harsh climates and good reproduction parameters as well as a marked mother instinct. Therefore, these breeds are often used in crossbreeding programmes. Beside the above-mentioned characteristics, our results indicate that the investigated breeds may be effectively used in crossing-out breeding programmes for eliminating valine at position 136 of PrP.     

Thyroid activity in relation to growth rate and body composition in four breeds of sheep

Four breeds of sheep, Hampshire, Southdown, Cheviot and Scottish Blackface, which differ in mature body size and body composition were intensively reared under an ad libitum or a restricted feeding regime. Thyroid activity was assessed at 13 weeks of age by the¹³¹I uptake method. Slaughter at 24 weeks (ad lib) or 32 weeks (restricted) was followed by carcass dissection. The anticipated differences in body type represented by the 4 breeds was confirmed in terms of size and fatness. The Hampshires had the highest growth rate (liveweight for age) and the lowest thyroid uptake, and the breed differences in thyroid activity were shown to be independent of liveweight. Thyroid activity was positively related to growth rate in the Hampshires and negatively related to growth rate in the 3 other breeds. No association could be found however between the thyroid activity and the proportionate growth of body fat or lean. None of these conclusions were affected by a mild restriction in feed intake.     

Evaluation of Egyptian sheep production systems: II. Breeding objectives for purebred and composite breeds

Objectives for this study were to estimate relative economic weights for performance traits for two native and two composite sheep breeds under two management systems in Egypt. Breeds studied were Rahmani (R), Ossimi (O), 3/4R-1/4Finnish Landrace (RFR), and 3/4O-1/4Finn (OFO); OFO and RFR were composite breeds. Management systems were one mating season per year (1M) and three mating seasons per 2 yr (3M). A dynamic computer model was used to simulate animal performance and enterprise efficiency and profit. Input parameters for the model were obtained from published results and analyses of data collected from experimental flocks of the same genetic stocks in Egypt. Responses for two measures of life-cycle feed conversion and one measure of enterprise profit were evaluated. Life-cycle feed conversion was calculated as kilograms of TDN input per kilogram of empty body weight output (TDN/EBW) and kilograms of TDN input per kilogram of carcass lean output (TDN/CLN). Profit was measured as annual gross margin/ewe (GM/EWE). Traits evaluated were conception rate (CR), lambing rate (LR), mortality rate (MR), mature weight (MW), and milk production (MK). Based on responses to percentage changes in trait means, CR was most important for TDN/EBW, followed by LR and MR. For TDN/CLN, LR, MR, and CR were most important. For GM/EWE, CR was most important, followed by LR, MW, and MR. In the systems studied, there was little response to changes in MK. Based on changes in GM/EWE per genetic standard deviation change, LR was most important, followed by CR, MR, MW, and MK in all systems. Relative economic weights for O and OFO were similar, as were weights for R and RFR. Differences in economic weights between management systems for the same breed were not large enough to justify separate selection lines within breeds.     

Evaluation of a cattle rapid test for early pregnancy diagnosis in sheep

Tropical Animal Health and Production - The early pregnancy diagnosis allows optimizing production and timely management correction, with a greater reproductive output of livestock. The Idexx Rapid...     

Anatomical characterization of hoof growth pattern in six Iranian sheep breeds and its possible implication for trimming recommendations

Tropical Animal Health and Production - The objective of this study was to compare hoof anatomy, hoof growth pattern, and hoof weight-bearing surface of six different Iranian sheep breeds to...     

The impact of a transgene for ovine growth hormone on the performance of two breeds of sheep

The effect of a transgene encoding ovine growth hormone and regulated by a metallothionein promoter was examined in progeny of 69 Merino ewes and 49 Poll Dorset ewes that were inseminated by rams heterozygous for the gene construct. The presence of the transgene had no effect on the progeny from one of the three rams used, as evinced by a normal concentration and secretion pattern of growth hormone and normal growth rate and fatness. In progeny from the other two rams that bore an actively transcribed and translated copy of the transgene, the mean concentration of growth hormone in the plasma was twice that of controls, but the pulsatility of secretion was lost. These animals grew faster (P < 0.001) and were leaner (P < 0.001), but had a greater parasite fecal egg count (P < 0.001). The impact of the transgene differed between breeds with greater wool growth rate (P < 0.01) and live weight increase (P = 0.06) in Merino progeny compared with Poll Dorset cross. At 18 mo of age, the depth of the eyemuscle was decreased (P < 0.001), particularly in female sheep (P < 0.01). The results indicate that the production effects of genetic manipulation may depend on the age, the breed, and the sex of the animal. Furthermore, the transgene may fail to be expressed in some progeny so that its activity cannot be detected, even though the sheep bear the DNA construct.     

Genetic parameters for early lamb survival and growth in Scottish Blackface sheep

The objectives of this study were 1) to estimate the heritability of lamb survival and growth in the Scottish Blackface breed; 2) to examine the relationship between lamb survival and live BW; and 3) to investigate the possibility of using lamb survival in a breeding program for this breed. The data used for the analyses contained information about survival and live BW at different ages on 4,459 animals. The records were collected from 1988 to 2003 in a Scottish Blackface flock. Live BW was recorded every 4 wk from birth to 24 wk. Survival was defined either by perinatal or postnatal mortality (up to weaning at 12 wk), or as cumulative survival to 1, 4, 8, and 12 wk. The pedigree file comprised 1,416 dams and 178 sires. A sire model was used to estimate genetic parameters for binary survival traits. Heritabilities of BW traits, and phenotypic and genetic correlations between BW and between survival and BW were estimated by fitting an animal model. Further, correlations of survival with live BW were estimated by using a Markov chain Monte Carlo threshold model, implemented by Gibbs sampling. The heritability estimates for cumulative lamb survival declined from birth onward (from 0.33 to 0.08), and postnatal survival had a heritability of 0.01. The direct and maternal heritabilities for BW traits ranged from 0.08 to 0.26 and from 0.06 to 0.21, respectively, whereas the maternal environmental component was between 0.04 and 0.16. The genetic correlations between BW traits at different ages were high. The genetic and phenotypic correlations between survival and BW were always positive (ranging from 0.04 to 0.54), so there was no antagonism between these traits. Therefore, it is possible to simultaneously improve both survival and live BW in a breeding program for this breed.     

Conidiobolomycosis in sheep in Brazil

Conidiobolomycosis is reported in the state of Piauí, in the semiarid region of northeastern Brazil. Affected sheep had depression, weight loss, serous or mucohemorrhagic nasal discharge, and cranium-facial asymmetry from exophthalmos of 1 eye, generally with increased volume of the eyeball, keratitis, and corneal ulceration. At necropsy of 60 sheep, friable masses were observed in the posterior region of the nasal cavity, often destroying the ethmoturbinate bones. Frequently, the lesions invaded the nasal sinuses, cribiform plate, orbit, and brain. The masses were irregular, granular with moist surfaces, and soft and friable with white, yellow, or tan coloration. Dissemination of the lesion to lungs was observed in 27 sheep, to the brain in 26, to lymph nodes in 3, to the kidney in 2, and to the gallbladder and heart in 1. The microscopic examination showed granulomatous inflammation composed of central necrosis surrounded by lymphocytes, epithelioid and giant cells, and fibrous tissue. In all lesions, negatively stained structures representing hyphae were surrounded by Splendore-Hoeppli material. Coagulative necrosis, thrombosis, and vasculitis were also observed. Grocott methenamine silver stain showed 8-30-microm-thick hyphae, rarely septate or ramified, irregular in shape, and with black contoured wall, sometimes with bulbous dilatation in the extremities. On electron microscopy, the hyphae had a thick double wall surrounded by cellular remnants and an inflammatory exudate. Conidiobolus coronatus was isolated from the lesions of 6 sheep. Conidiobolomycosis is an important disease of sheep in the state of Piauí, and other regions of northeastern Brazil.     

Dental configuration among different breeds of sheep

Three breeds of sheep, Southdown, Suffolk and Romney, and two mixed breeds, Border Leicester over Romney and Coopworth over Romney, managed identically on a research station, where they were free from culling and allowed to live their natural life, had their dental configuration examined. The sheep were divided into age groups with 10 sheep in each. The least variation was found in the relation of the upper dental pad to the lower jaw. The most statistically significant differences were found in the first age group: one year six months. The Suffolk breed was noticeably different from the others. Deepened gingival sulci, as well as the inconsistency of bleeding after probing associated with labial gingivitis highlighted the problems of using these latter criteria as indicators of health or disease among sheep on the basis of a single examination.